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1、Chapter 1 Water Relationship in Plant 26+3一、Term translation and definition：1.Water potential (w)水势每偏摩尔体积水的化学势差。水势反应了植物系统中化学反应以及运动的能力。Water potential is defined as the difference in free energy per unit volume, between metrically-bound, pressurized, or osmotically-constrained water and pure water. w
2、 reflects the capacity for chemical reaction and movement in plant system2.Apoplast and symplast 质外体和共质体 质外体是指原生质之外的结构部分及空间，包括细胞壁、细胞间隙和木质部的导管等无生活物质的各个部分。 共质体是指活细胞内的原生质体通过细胞与细胞间的胞间连丝互相连接成的一个连续的结构。A continuous system consists of cell wall, cell space(interplace) and vessel of xylem, except protoplast,
3、 considered as a non-life part in the plant.A continuous system consists of protoplast, plasmodesma and plasmic membrane, considered as a life part except apolast.3.Free water and bound water 自由水和束缚水靠近胶粒而被胶粒吸附不易移动的水分称为束缚水；距离胶粒较远而可以自由移动的水分称为自由水。其实这两种水分状态的划分是相对的，它们之间没有绝对的界限，只是物理性质有所不同。自由水参与各种代谢作用，作为溶剂
4、易凝固，而束缚水则不参与。【定义+相对+作用】Free water: It does not bind to components of cell tightly and moves freely in the plant. Special characters: participate in metabolism, take as solvent and easily freeze 。bound water：It binds to components of cell tightly and does not move freely in the plant. Special charact
5、ers: do not participate in metabolism, do not take as solvent and do not easily freeze 。4.Bleeding and guttation 伤流和吐水 吐水：没有受伤的植物如果处于土壤水分充足、大气温度和湿度较高的环境中，在蒸腾作用大为减弱以至停止的环境中，叶尖或叶缘分泌液体的现象。 伤流：如将生长旺盛的植物，从地面切断，可见到有汁液从残茎的切口溢出，这种现象。Bleeding: a phenomena that the sap flows out from the wounded part. It is c
6、aused by root pressure.Guttation: when soil has enough water and atmosphere is warm and higher RH, often in the early mourning, unwounded leaf can secret sap from tip or margin of leaf. It is an index for health seedlings. 5.Root pressure 根压 由于根系的生理活动使液流从根部沿木质部的导管上升的压力。根压的大小取决于跟生理活动的强弱。Root pressure
7、 is a power which pushed water to mount along vessel, depending on physiological activity of root.0.1-0.2MPa, much or less depending on stronger or weaker physiological activities of the root.6.Soil available water土壤可利用水分 指土壤中可以直接被植物吸收利用的水分，即土壤中高于永久萎焉系数值的含水量部分。It is referred as the water that can di
8、rectly be taken up and utilized by plants, which water content is higher than wilting coefficient in the soil.7.Temporary wilting and permanent wilting 暂时萎焉和永久萎焉水分亏缺严重时，植物细胞因失水而松弛，靠膨压维持挺立状态的叶片和茎的幼嫩部分下垂，这种现象叫萎焉。暂时萎焉：当蒸腾作用强烈，根系吸水及转运水分的速度较慢，不足以弥补蒸腾失水时，发生暂时萎焉，当蒸腾速率降低时，根系吸水的水分足以弥补失水，消除水分亏缺，即使不浇水或者通过
9、荫蔽能恢复，这种靠降低蒸腾就能消除的萎焉。永久萎焉：如果土壤中缺少植物可利用的水，那么即使降低蒸腾，植物仍不能消除水分亏缺，也不能恢复原状，需要浇水才能得到缓解。【定义+症状+消除方法】The wilting is caused by loss of equilibrium between water absorption and evaporation (main transpiration). Transpiration is larger than absorption. It can be recovered by shading or in the evening upon decr
10、easing in transpiration, but not by watering.The wilting is caused by no available soil water, plant can not absorb water from the soil. It can be recovered by watering or water spring, but not by decreasing in transpiration.8.Transpiration pull蒸腾拉力这种由于蒸腾作用产生的一系列水势梯度使水分沿着导管上升的力量称为蒸腾拉力。蒸腾拉力与根新陈代谢无关，并
11、且是植物水分吸收的主要动力。A power driving water upward along xylem vessel, and is decided by a gradient of water potentials due to transpiration. It is independent of root metabolism and is the main power for water absorption.9.Transpiration coefficient (water requirement)蒸腾系数（需水量）植物制造1克干物质所需水分的克数，大部分作物为500-100
12、g。【定义+举例】The water (unit: g) demanded by plants to produce 1 g dry weight.10.Transpiration efficiency (ratio)蒸腾效率蒸腾效率是指植物每消耗一千克水时所形成的干物质g。The dry weight increased（unit: g）after consuming 1kg water by plants.11.Transpiration rate 蒸腾速率植物在一定时间内单位叶面积蒸腾的水量。The water lost through transpiration by given si
13、ze of the leaf in a given length of time (g/m2 s).12.Critical period of water 水分临界期水分临界期是植物对水分不足最敏感且最易因此受损伤的时期，但这一时期，植物的蓄水量并不是最大的。A period during which plant is most sensitive to water deficiency and is most easily injured by water deficiency, but the water requirement is not always largest at
14、 that period13.Transpiration-cohesion-tension theory蒸腾-内聚力-张力学说水分具有较大的内聚力足以抵抗张力，保证由叶至根的水柱不断，从而使水分能够源源不断的从根部运至地上部分。Water can be transported in a continuous water column because water cohesion is larger than its tension. 14.Osmosis absorption渗透性吸水渗透指溶剂分子通过半透膜依水势梯度移动的现象。15.imbibition absorption 吸胀吸水是未形
15、成液泡的植物细胞戏水的主要方式，其大小与植物细胞内的物质种类有关。如蛋白质>糖类>脂肪16.metabolism absorption 代谢性吸水17.Semipermeable membrane 半透膜18.Plasmolysis and Deplasmolysis 质壁分离与质壁分离复原19.ssolute potential 溶质势20.ppressure potential 压力势21.mmatric potential 衬质势细胞内胶体物质（如蛋白质、淀粉、细胞壁物质等）对水分吸附而引起水势降低的值，为负值。22.Water channel proteins or aqu
16、aporins水通道蛋白或水孔蛋白23.Stomatal transpiration气孔蒸腾24.Law of micro-pore diffusionperimeter diffusion小孔扩散定律周长扩散25.Stomatal complex 气孔复合体保卫细胞guard cell及邻近细胞neighboring cell或副卫细胞accessory cells/ subsidiary cells26. permanent wilting coefficient: 永久萎焉系数是指当植物发生永久萎焉时，土壤中尚存的水分含量占土壤干重的百分比。二、Questions:1. Why do w
17、e not irrigate plant with cold water at noon in the sunny summer day?In the summer noon, because of high temperature and low relative humidity, the transpiration is very high. Thus the root has to absorb much water to keep the water equilibrium. If plants are watered with cold water, which will decr
18、ease the soil temperature and then decrease the water absorption by root, the plants will wilt even death by disorder of body water balance as loss of water by the transpiration is less than uptake of water by root.2. Why should we keep a bulk of soil of root and cut off most of leaves when transpla
19、nt big tree? 3. Why should we not apply a large number of fertilizers to plant in one time? Because that the application of a large number of fertilizer to plant in one time may result in the rapid increase of soil solute concentration. Since the root absorbs water from the soil only when the water
20、potential of the root cell is lower than that of the soil solution, the high soil solute concentration means very low water potential of soil solution, which prevents the absorption of water by the root. It can bring about the deficiency of water and wilting of plant, which damages the plant.40Chapt
21、er2 Plant mineral nutrition 24+3一、Term translation and definition1.Essential elements and all element names Essential elements, in brief, is necessary for plants to grow and develop, and a deficiency of the element makes it impossible for the plant to complete a normal life cycle【定义+缺症】. Carbon/ hyd
22、rogen/oxygen/Nitrogen/ phosphorus/ potassium/ sulphur/ calcium/ magnesiumIron/copper/zinc/manganese/molybdenum/chlorine/nickel/boron2. Macroelements (Major elements)是指植物需要量较大的元素，在植物体内含量较高，占干重的0.1%以上。它们是The elements are in large quantity required by plants and are higher contents(higher than 0.1% of
23、the dry weight) in plant body, including C, H, P, S, K, C, Mg, Si.3. Microelements (Trace elements)是指植物需要量较少，在植物体中含量较低，常占干重的0.01%一下。它们是The elements are in small quantity required by plants and are lower contents(lower than 0.01% of dry weight)in plant body, including Fe, Mn, B, Zn, Mo, Cu, Cl, Ni.4.
24、Beneficial elements 有益元素有益元素是指能促进植物生长发育，但不为植物普遍所需的，或在一定条件下为植物所必须，或只有某些植物生长所必须的元素。A group of elements to enhance plant growth and development, but they are not necessary for plants. It can become necessary for special plants or conditions, like Si required by rice, Al by tea, and Na by beet.5.Physiol
25、ogically acid , alkaline and neutral salts 生理酸性盐、生理碱性盐、生理中性盐由于植物的选择性吸收，引起阳离子吸收量大于阴离子吸收量使溶液变酸的这一类盐，称为生理酸性盐，如氯化铵NH4Cl，硫酸铵(NH4)2SO4、KCl、CaCl2等；相反，植物对阴离子的吸收量大于阳离子的吸收量，溶液pH上升的这一类盐，称为生理碱性盐。如硝酸钾KNO3，硝酸钙Ca(NO3)2；还有一类盐，植物对其阴阳离子的吸收相等，不因植物的吸收引起溶液pH的改变，称为生理中性盐，如硝酸铵NH4NO3。【注：N的吸收较多】6. Solution (water) culture (h
26、ydroponics) 水培法是把植物生长所需的各种元素按一定的比例，适宜的pH配制成溶液，用以培养植物的方法。可以用来判断必需元素的种类、作用以及其缺素症状。【定义+作用】It is a kind of method to identify plant essential elements and study for function of the elements and mechanism of its absorption. 7.Critical period of nutrition 营养临界期植物对缺乏矿质元素最敏感，缺乏后最易受害的时期。8.Nutrition maximum p
27、eriod 营养最大效率期 这个时期对矿质元素需要量最大，吸收能力强，若能满足肥料需求，增产效果十分显著。9.Donnan equilibrium 杜南平衡植物怎么可以逆浓度梯度积累矿质离子 细胞内可扩散正负离子浓度乘积等于细胞外液可扩散正负离子浓度乘积时的状态. The product of the diffusible anions and cations inside of the cell is equal to outside of the cell.10.Ion channel theory离子通道学说Carrier theory 载体学说.Ion pump theory 离子泵学
28、说The gate can be controlled by voltage or ion concentration, even by light, hormones or other stimuli.11.Antagonism and synergism action 拮抗作用和协同作用Competition: one ion inhibits the absorption of another ion一种离子的存在促进另一种离子的吸收，从而提高了后者的有效性称为协同作用。one ion enhances the absorption of another ion because it m
29、ake the latter available. 12.Balanced solution 平衡溶液 The culture solution contains a range of all kinds of essential elements and pH, and makes plant grow well.25.Toxicity of single salt and ion antagonism单盐毒害和离子拮抗Single salt resulted in plant poisoning is called toxicity of single salt. Ion antagoni
30、sm is referred as the interaction among ions can limit toxicity of single salt。14. CaM (calmodulin)钙调蛋白 Hydrophyte水生植物 Halophyte盐生植物 Nitrate reductase 硝酸还原酶Nitrite reductase 亚硝酸还原酶 Rhizosphere根际Foliar nutrition叶面营养Elements reutilization元素再利用15,平衡溶液 Balanced solution·Elements reutilization·
31、营养最大效率器：Nutrition maximum period·叶面营养 Foliar nutrition·离子通道 Ion channel· CaM(calmodulin) 钙调蛋白，钙离子的吸收是依赖 的过程。为什么不能从外面的高浓度到里面去。因为是主动运输的过程！越是有很多假说机理的地方，看了能理解那个思路就可以了！ 必须元素的生理作用及缺素症状（如NPK）以小问题的形式出现，以填空和选择的形式出现· 如何提高植物养分利用效率？二、Questions1. Briefly describe the factors affecting nutrien
32、ts uptake by plant roots.内部因子（intrinsic factors）1、 离子直径（越小吸收越快）2、 化合价（valency）：不带电荷>正负一价>正负二价>正负三价环境因子1、 光：光是source of driving force, 越高越好。光和蒸腾作用2、 温：在一定范围内，越高越好，但是过高和过低都导致下降。使代谢增强，酶活性增强3、 水：营养元素通过集流和扩散转运。保持土壤适当的含水量十分重要4、 氧气：氧气增加了根的呼吸作用，增强了离子吸收。在一定范围内，随着氧分压的增加，吸收速率增加。5、 pH：影响根表面的电荷情况，以及离子的生
33、物可利用（bioavailability）6、 离子浓度：当浓度低时，随着浓度增加而吸收增加，但是当超过一定浓度时，吸收饱和。7、 营养元素之间的相互作用（interactions between nutrients）:包括离子之间的竞争competition和协作synergism。8、 有毒物质：根系1) Intrinsic factorsa. Ion diameter. The ion diameter is smaller, the uptake rate is faster.b. Valency. The uptake rate often increases in the foll
34、owing order:Uncharged molecules > Cat+ and An- > Cat2+ and An2- > Cat3+ and An3- 2) Environmental factorsa. Light. Light is the source of driving force, the increase of light intensity can enhance the nutrient uptake.b. Temperature. In a certain range, the nutrient uptake rate rises along w
35、ith the increasing soil temperature. But both the excessive high and low temperature may make the uptake rate decrease.c. Water Except Interception, nutrients are transferring through mass-flow and diffusion, all of which are dissolved in soil solution. It is important to maintain a suitable soil wa
36、ter content d. O2. In a certain range, the nutrient uptake rate rises along with the increasing oxygen partial pressure. The oxygen facilitates the respiration, which promotes nutrient uptake.e. pH. Influences the charge of roots surface and the bioavailability of nutrientsf. Concentration. In the l
37、ow concentration, the nutrient uptake rate rises with the increasing ion concentration. But when the concentration is high enough, the ion uptake is saturated.g. Interactions between nutrients, including competition which means one ion inhibits the absorption of another and synergism which means one
38、 ion enhances the absorption of another2. What are the mineral nutrients with deficient symptoms appearing on older leaves or younger leaves? Describe the most typical symptoms of one of them for each class.可再利用元素缺素症从老叶开始 N、P、K、Mg、Zn 。B 特殊 不能再利用元素缺乏时幼嫩部位先出现病症 。S、Ca、Fe、Mn、B、Cu、Mo等,其中以Ca最难再利用 。Ca defi
39、cient symptoms：Tip meristem necrosis (生长点坏死)；Notch in young leaf；Tomato“脐腐病”，cabbage “干心病”S deficient symptoms：S-deficient plant looks smaller and its young leaf exhibits chlorosis to white. Flowering and setting delay in S-deficient rapeFe：Leaf chlorosis in vein islets. Thereafter, the young leaves
40、 become yellowish to white. The leaves are thinner and flaccid (薄而光滑)with less pubescences (表皮毛).3. Describe main symptoms of N, P and K deficiency in plant. Nitrogen deficient symptoms1. Growth stun, roots show thinner and longer, less branches and tillerings少分支和分蘖2. Older leaves turn yellow3. Base
41、 of stem appears vinicolor in N-deficient maize（anthocyanin accumulation）P deficient symptomsExtremely stun，young leaves appear dark-green in color and older leaves and base of stem exhibit vinicolor.幼叶暗绿色或者发红。K deficient symptoms最明显的缺K症状在叶缘1. Stem weak, lodging easily, less resistance to stresses.2
42、. Older leaves develop mottling (色斑) or chlorosis, followed by necrotic lesions at the leaf margins.“焦边”Chapter3 Photosynthesis in Plant 58+5一、Term translation and definition 【 按阶段记忆】1. Greenhouse effects温室效应阳光主要以短波辐射照到地面，使地面及物体温度升高，它们则以长波辐射形式向宇宙空间散失热量，由于这些温室气体不能透过长波辐射，把一部分地球上辐射除去的能量又反射到地球，使地球散热下降。因
43、这一现象与天然温室加热相同，故称温效应室。Sunlight come to the surface of the earth mainly in the form of short wave, and objects on the earth absorb the energy and then emit the excess energy to the sky in the form of long wave light, but greenhouse gases make it very hard for the long wave light to pass through, thus
44、the temperature on earth goes up. This phenomena is quite similar to the nature greenhouse, thus it is called greenhouse effect.2. Reaction center pigments 反应中心色素是指吸收光或由集光色素传递而来的激发能后，发生光化学反应引起电荷分离的光合色素，在高等植物中作用中心色素是吸收特定波长光子的叶绿素a。【定义+举例】can absorb light energy or accepted the energy transferred from
45、the antenna pigment, ant then convert that into electric energy. A few Chla反应中心：3. Light harvesting pigments (Antenna pigments) 集（捕）光色素（天线色素）是指只能吸收和传递光能、不进行光化学反应的光合色素。叶绿素a/b、类胡萝卜素都可作为集光色素。【定义+举例】Only play roles in light absorption and transfer but does not undertake photochemical reaction. Chlb, car
46、otenoids, Chla.4. Photosynthetic unit 光合单位 （没有）由250-300个叶绿素和其他集光色素分子组成的，能完成1个光量子吸收并转化的色素蛋白复合体。通常由集光色素蛋白复合体和作用中心蛋白复合体组成。Photosynthetic unit is a photosynthetic pigment and protein complex. It functions as a unit for absorption and change of 1 photon into a charge, in which there are about 250-300 chl
47、 molecules.5. Photosynthetic chain 光合链 X光合链是由两个光系统和若干电子传递体，按一定的氧化还原电位依次排列而成的体系。A system consists of two photosystems and some electron (or hydrogen) transporters, which are exactly arranged in thylakoid membrane according to their oxidative-reductive electric potentials.6. PQ shutter PQ穿梭 XPQ穿梭：在光合电
48、子传递过程中PQ使间质中H+不断转入类囊体腔，导致间质pH上升，形成跨膜的质子梯度。7. Photophosphorylation 光合磷酸化PSP X光合磷酸化是指在光合作用中由光驱动并在跨类囊体膜的质子梯度的能量吧ADP和另算合成ATP的过程。8. Primary reaction原初反应 X原初反应是指光合作用中从叶绿素分子受光激发到引起第一个光化学反应为止的过程，其中包含色素分子对光能的吸收、传递和转换的过程。9. Assimilatory power 同化力X光合作用前两阶段结束形成活跃的化学能ATP和NADPH合称为“同化力”。10. Photorespiration 光呼吸是指高
49、等植物的绿色细胞在光下吸收O2放出CO2的过程11. CO2 Compensation and saturation points 二氧化碳补偿点和饱和点12. Photorespiration 光呼吸 填空是指高等植物的绿色细胞在光下吸收O2放出CO2的过程。光呼吸过程中几种主要的化合物如乙醇酸（Glycolic acid），乙醛酸，甘氨酸都是二碳化合物（dicarboxylic acid二羧酸），因此光呼吸又称为C2环。光呼吸主要在叶绿体、过氧化物酶体Peroxisome以及线粒体Mitochondrion配合下完成，其强度主要受到Rubisco的活性调节。推测起作用为(1)防止高光强对光
50、合器的破坏；(2)防止O2对光合碳同化的抑制作用； (3)消除乙醇酸毒害和补充部分氨基酸【定义+底物+场所+限制条件+作用】13. Light Compensation and saturation points 光补偿点和饱和点14. Quantum efficiency 量子效率 XThe plant assimilates number of CO2 by absorption of 1 molecule of quantum.15. Quantum requirement 量子需要量：During photosynthesis plant requires number of quan
51、tum for assimilating 1 molecule of CO2 (or releasing 1 molecule of O2).16. Fluorescence and phosphorescence 荧光现象和磷光现象X叶绿素溶液在透射光下呈绿色，而在反色光下呈红色（Chla 为血红色，Chlb为棕红色），这种现象叫做荧光现象。因为色素分子在接收光的能量后，由稳定的基态变成激发态，在恢复基态时以光的形式释放了一部分能量，而这部分光的波长范围恰好为红光，即出现了荧光现象。If a sufficiently concentrated solution of either Chl a
52、 or Chl b or mixture of chloroplast pigments is illuminated, a red light called fluorescence can be seen. It is light production accompanying rapid decay of electrons in the excited state. 10-9s.停止光照后，叶绿素荣也能辐射出极微弱的红光，这种光成为磷光。磷光寿命较长After stopping the lighting, the Chl can still emits dark red light i
53、n the dark, this is called phosphorescence. It can last longer than fluorescence, but the strength of it is much smaller. 17. Noncyclic, cyclic and pseudo-electron transports 非环式、环式、假环式电子传递(1)非环式光合电子传递和非环式光合磷酸化。涉及两个光系统。产生O2, NADPH和ATP，占总电子传递的70%以上。(2) 环式光合电子传递和环式光合磷酸化。只涉及PSI，能产生ATP, ATP的补充形式。占总电子传递的
54、30%左右。(3) 假环式电子传递和假环式光合磷酸化。涉及两个光系统，形成超氧自由基。对植物体造成危害。在强光下，CO2不足，NADPH过剩下发生。18. Red drop 红降：用远红光处理下，光被吸收但是光合效率下降的现象19. Emerson enhancement effect 爱默生增益效应 XQuantum efficiency is enhanced by two beams of light（红光+远红光）20. Hill reaction 希尔反应X水在光下电解释放氧的过程With the isolated chloroplasts and artificial electr
55、on acceptors, light-driven reduction of the electron acceptors was accompanied by O2 evolution.21. Photochemical reaction 光化学反应XPhotochemical reaction is defined as the oxidative and reductive reaction of pigments (Chla680 or Chla700) driven by photon. 22. Photosynthetic rate (Pn,molCO2 ( O2 ) /m2&#
56、183;s) X光合速率通常是指单位时间、单位叶面积吸收的二氧化碳的量或者放出氧气的量，或者积累干物质的量。Net photosynthetic rate (Pn) =Total photosynthetic rate (Pt)respiratory rate (Rd).23. Carbon dioxide assimilation 碳同化X24. Accepter 原初电子受体Donor 原初电子供体Excited state 激发态 25. Inductive resonance 诱导共振Inductive resonance is referred as a neighboring pi
57、gment molecule is excited, while an excited-state pigment molecule return to its ground state26. Photosystem 光系统 Cytochrome complex 细胞色素复合体ATP synthase ATP合成酶27. Plastoquinone(PQ) 质体醌 Plastocyanin（PC）质蓝素 Ferredoxin(Fe-S) 铁氧还蛋白28. it transports electron to FNR for reduction of NADP to NADPH2，or to Cy
58、tb6 for cycling electron transport. Photosynthetic pathway 光合作用代谢途径Carboxylation 羧化阶段mesophyll cell 叶肉细胞Chloroplast 叶绿体Envelope 被膜（叶绿体被膜）Thylakoid 类囊体 Stroma间质Rubisco RuBP羧化酶/加氧酶 Carotenoid 类胡萝卜素Xanthophyll 叶黄素Glucoprotein 糖蛋白 Porphyrin 卟啉 Phytol叶醇29. Photoinhibition光抑制强光下光合速率降低30. Oxygen evolving c
59、omplex 放氧复合物31. Crassulacean acid metabolism (CAM pathway)景天科代谢途径32. Rubisco RuBP羧化酶/加氧酶Ribulose-1,5-bisphosphate carboxylase/oxygenase, most commonly known by the shorter name RuBisCO, is an enzyme that is used both in the Calvin cycle to catalyze incorporation of CO2 into organic form in the first
60、 major step of carbon fixation and in the photorespiration to catalyze the condensation of O 2 with ribulose-1,5-bisphosphate. The rubisco of plants has eight large subunits each containing an active site which can binds both the CO2 and O 2, and eight small subunits whose function is not well under
61、stood.33. Solar energy utilization光能利用同化力、光合链、光合速率、PQ穿梭、光呼吸、C3C4 and CAM plantsRubisco 酶结构看一下，知道作用二、Questions1. Why can we say that Rubisco is a key enzyme for photosynthesis? P892. How to improve photosynthetic productivity in physiology and production?如何提高光合产量Economic yield= photosynthetic (area &
62、#215;rate× time)-Rd × harvest indexThe main method to increase the solar energy utilization efficiency in physiology is to make plants convert more solar energy to chemical energy, i.e. increase the biomass yield per unit. Therefore, we should try to reduce the loss by respiration, leakage
63、, leaf reflection and transmission and enhance the rate of light transformation.(1) Increase the area of photosynthesis. 增加光和面积Concretely increase the leaf area index（LAI）, which is one of the most important methods to achieve high yield.a. Arrange the crop in proper density.合理密植 Arrange the crop ne
64、ither too thinly nor too densely, which may both result in low yield.b. Supply the crop with sufficient nutrition and water.充足营养 This method can make rapid LAI increase in the early stage and avoid too huge LAI in the late stage, which prolong the longevity of the photosynthetic organs and increase the yield.c. Change the crop type.改变品种 The crop species with short stem, thick leaves are believed to have high yield.(2) Prolong the period of photosynthesis, 延长光和时间which means to prolong the period is available for photosynthesis in a year.a. Increase the Cropping Index, which m
